Diesel-fuelled engines and/or hydraulic systems are frequently used in cold environments such as in the winter months in temperate zones or year round in far northern or southern geographies. The viscosities of diesel, hydraulic oils or other fluids increase significantly as ambient temperatures decrease to the point were they can form gels and/or waxes. In addition, cold conditions impede the transmission of thickened diesel fuel oils from their storage tanks to engines thereby interfering with and/or preventing engine starting. Smooth and safe operation of hydraulic-controlled attachments can also be adversely affected by cold-thickened hydraulic oil through reduced and impaired flow rates in response to manipulation of the hydraulic controls. Additionally, cold-thickened hydraulic oil imposes significant mechanical stresses on hydraulic pumps often resulting in accelerated wearing and deterioration of the pumps' components and periodically, in pump failure.
Large volumes of crude and refined petroleum products are commonly stored in bulk reservoir tanks at locations such as drilling sites, refineries, and storage depots. Transfer and transmission of such stored petroleum products can be significantly debilitated as their viscosities increase as a consequence of cold weather conditions.
Heat-exchange apparatus have been developed for installation in portable and/or fixed storage tanks for raising or lowering the temperatures of oil products stored therein as exemplified by U.S. Pat. Nos. 6,380,523; 5,423,373; 5,029,634; 4,926,830; 4,865,005; 4,726,346 and 4,237,850. However, numerous problems are associated with such prior art including complexity of design and associated high costs of production, variable and uneven heat-transfer profiles, and high energy input requirements for satisfactory performance. The heat-exchange apparatus described in WO2007/137406 overcomes many of these problems associated with the prior art devices, but despite its success, some issues remain. For example, the apparatus can be awkward to mount on a storage tank. Additionally, while the helical turbulator described in WO2007/137406 provides excellent performance, it is somewhat difficult to manufacture and must be precision engineered in a manner which is beyond the capacity of many engineering firms.